Fiber optic communication systems are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities (e.g., data and voice) to customers. Fiber optic communication systems employ a network of fiber optic cables to transmit large volumes of data and voice signals over relatively long distances. Optical fiber connectors are an important part of most fiber optic communication systems. Fiber optic connectors allow two optical fibers to be quickly optically connected without requiring a splice. Fiber optic connectors can be used to optically interconnect two lengths of optical fiber. Fiber optic connectors can also be used to interconnect lengths of optical fiber to passive and active equipment.
A typical fiber optic connector includes a ferrule assembly supported at a distal end of a connector housing. A spring is used to bias the ferrule assembly in a distal direction relative to the connector housing. The ferrule functions to support an end portion of at least one optical fiber (in the case of a multi-fiber ferrule, the ends of multiple fibers are supported). The ferrule has a distal end face at which a polished end of the optical fiber is located. When two fiber optic connectors are interconnected, the distal end faces of the ferrules abut one another and the ferrules are forced proximally relative to their respective connector housings against the bias of their respective springs. With the fiber optic connectors connected, their respective optical fibers are coaxially aligned such that the end faces of the optical fibers directly oppose one another. In this way, an optical signal can be transmitted from optical fiber to optical fiber through the aligned end faces of the optical fibers. For many fiber optic connector styles, alignment between two fiber optic connectors is provided through the use of an intermediate fiber optic adapter.
Fiber optic connectors often include strain relief boots mounted at proximal ends of the connector housings. Strain relief boots are designed to prevent the optical fibers within the fiber optic cables secured to the fiber optic connectors from bending to radii less than the minimum bend radii of the optical fibers when side loads are applied to the fiber optic cables. Example strain relief boot configurations are disclosed in United States Patent Application Publication Nos. US 2011/0002586 and US 2010/0254663; and are also disclosed in U.S. Pat. Nos. 7,677,812; 7,147,385; 5,915,056; 5,390,272; and 5,261,019.
A fiber optic connector is often secured to the end of a corresponding fiber optic cable by anchoring strength numbers of the cable to the connector housing of the connector. Anchoring is typically accomplished through the use of conventional techniques such as crimps or adhesive. Anchoring the strength numbers of the cable to the connector housing is advantageous because it allows tensile load applied to the cable to be transferred from the strength members of the cable directly to the connector housing. In this way, the tensile load is not transferred to the ferrule assembly of the fiber optic connector. If the tensile load were to be applied to the ferrule assembly, such tensile load could cause the ferrule assembly to be pulled in a proximal direction against the bias of the connector spring thereby possibly causing an optical disconnection between the connector and its corresponding mated connector. Fiber optic connectors of the type described above can be referred to as pull-proof connectors.
As indicated above, when two fiber optic connectors are interconnected together, the ferrules of the two connectors contact one another and are respectively forced in proximal directions relative to their housings against the bias of their respective connector springs. In the case of pull-proof connectors, such proximal movement of the ferrules causes the optical fibers secured to the ferrules to move proximally relative to the connector housings and relative to the jackets of the fiber optic cables secured to the connectors. To accommodate this relative proximal movement of the optical fibers, the fiber optic cables typically have sufficient interior space to allow the optical fibers to bend in a manner that does not compromise signal quality in a meaningful way. Typically, the bending comprises “macrobending” in which the bends have radii of curvatures that are larger than the minimum bend radius requirements of the optical fiber.
A number of factors are important with respect to the design of a fiber optic connector. One aspect relates to ease of manufacturing and assembly. Another aspect relates to connector size and the ability to provide enhanced connector/circuit densities. Still another aspect relates to the ability to provide high signal quality connections with minimal signal degradation.